Hypothesis, Operational Definitions & Ethogram

Hypothesis, Operational Definitions & Ethogram

Hypothesis: Captive male chimpanzees are more likely to engage in social behaviors with female chimpanzees than male chimpanzees in the wild.

Since research shows that females are more likely to engage in social behaviors in wild environments, males in captive environments may lead to increased interactions with other group members. Chimpanzees in the wild are not normally monogamous and do not engage much with their offspring, which leads to less parental care. Since these chimpanzees will be in an enclosed space with less females to mate with, they will tend to be more engaged with a specific female, leading to increased parental care. (Mitani, 2009).

Operational Definitions:

Sampling method: focal sampling

Data collection method: 3 minute intervals; 1-0 time sampling

Behavior Abbreviation Definition

1. Eating habits [EH 1 or 2] Eating, drinking or searching for food.

1=Eating, drinking or searching for food alone. 2=Eating, drinking or searching for food with others.

2. Grooming [GO OR GS] Touching, licking or intense visual

inspection of skin. GO=Grooming another individual by using hands or lips to part another individual’s hair. GS=Grooming ones-self by using their own hands to part their own hair (Proctor, et. al., 2011).

3. Social Play [SP 1, 2 or 3] Affiliative interaction of playful gestures.

1=Participate in solitary play, such as somersaults, pirouettes, tossing and tumbling with an object, and swinging in a tree. 2=Participate in dyadic play. Playful interactions between two individuals, such as rubbing, biting, tickling, wrestling or chasing one another. 3=Participate in larger group play, same as 2, except with 3 or more individuals (Lonsdorf, et. al., 2014).

4. Parental Care [PC 1 or 2] Caring of the youth. 1=Male more

responsible for caring of the youth. 2=Female more responsible for caring of the youth.

5. Aggression [AG 1 or 2] Individual performs an aggressive or

submissive behavior. 1=No aggression or low aggression. Does not include physical contact with one another. Charging displays, such as piloerection and branch shaking. 2=Moderate aggression with higher levels of physical contact with one another. Chasing and attack displays, such as hitting, kicking, pounding and dragging (Muller & Wrangham, 2004).

6. Sexual Behavior [SB 1 or 2] Individual interacts in sexual behavior,

either alone or with other individuals. 1=Mounting. 2=Masturbation. 3=Copulation. (Chelluri, et. al., 2012).

7. Vocalizations [VO 1, 2 or 3] Communication behaviors, such as

socializations and greetings. 1=Barking.

2=Pant-grunts (bobbing or crouching). 3=Screaming (Laporte & Zuberbuhler).

8. Traveling [TR 1 or 2] Movement from one place to another.

1=riding ventrally; infant clings to the belly of the mother, grabbing on to hair. 2=riding dorsally; infant sits/lays on mother’s back.

(Lonsdorf, et. al., 2014).

9. Caretaker Interactions [CI 1 or 2] Interactions, such as play and feeding,

between the chimpanzee and zoo caretakers. 1=Individual attends to staff for less than 3 seconds. 2=Individual attends to staff for more than 3 seconds. (Chelluri, et. al., 2012).

10. Proximity [PR 1, 2 or 3] The closeness of chimpanzees to one

another.1=sitting alone, not interacting with other chimpanzees. 2=sitting with one other chimpanzee and interacting in social behaviors. 3=sitting and interacting with a group of chimpanzees.


START TIME: 12:00 P.M.


Behavior [EH 1 or 2]

Behavior [GO or GS]


[SP 1, 2 or 3]


[PC 1 or 2]


[AG 1 or 2]


[SB 1 or 2]

Behavior [VO 1, 2 or 3]

Behavior [TR 1 or 2]

Behavior [CI 1 or 2]

Behavior [PR 1, 2 or 3]

3 min

6 min

9 min

12 min

15 min

18 min

21 min

24 min

27 min

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48 min

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57 min

60 min

63 min

66 min

69 min

72 min

75 min

78 min

81 min

84 min

87 min

90 min

93 min

96 min

99 min

102 min

105 min

108 min

111 min

114 min

117 min

120 min

123 min

126 min

129 min

132 min

135 min

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144 min

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168 min

171 min

174 min

177 min

180 min


Chelluri, G., Ross, S., Wagner, K. (2012). Behavioral correlates and welfare implications of informal interactions between caretakers and zoo-housed chimpanzees and gorillas. Applied Animal Behaviour Science, vol. 147, pp. 306-315. Doi:10.1016/j.applaim.2012.06.008.

Laporte, M., & Zuberbuhler, K. (2010). Vocal greeting behavior in wild chimpanzee females. Journal of Animal Behaviour, 80, 467-473. Doi:10.1016/j.anbehav.2010.06.005.

Lonsdorf, E., Anderson, K., Stanton, M., Shender, M., Heintz, M., Goodall, J., Murray, C. (2014). Boys Will Be Boys: Sex Differences in Wild Infant Chimpanzee Social Interactions. Animal Behaviour, vol. 88, pp. 79–83., doi:10.1016/j.anbehav.2013.11.015.

Martin, P., & Bateson, P. (1993). Measuring behaviour: an introductory guide.

Cambridge: Cambridge University Press.

Matsumoto, T. (2017). Developmental Changes in Feeding Behaviors of Infant Chimpanzees at Mahale, Tanzania: Implications for Nutritional Independence Long before Cessation of Nipple Contact. American Journal of Physical Anthropology, vol. 163, pp. 356–366., doi:10.1002/ajpa.23212.

Mitani, J. (2009). Male Chimpanzees form enduring and equitable social bonds. Animal Behaviour, 77(3), 633-640. Doi:10.1016/j.anbehav.2008.11.021.

Muller, N., & Wrangham, W. (2004). Dominance, aggression and testosterone in wild

chimpanzees: A test of the ‘challenge hypothesis’. Animal Behaviour, 67(1), 113-123.


Proctor, D., Lambeth, S., Schapiro, S., Brosnan, S. (2011). Male Chimpanzees’ Grooming Rates Vary by Female Age, Parity, and Fertility Status. American Journal of Primatology, doi:10.1002/ajp.20964.

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